At present, the growing interest for the environment contributes to a significant increase of the recycling or recovering of paper. On the other hand, this means that more and more recovered paper is recycled into new paper. Numerous technical developments aim to expand the areas of use for recovered paper.
The kind of purity that is required for certain paper products can be accomplished whether at the time of the reception of the recovered paper as in the case of shops, companies and industries. On the other hand, the necessary characteristics must be achieved for production by selecting and organizing the paper. This applies to the majority of recovered paper coming from private sources. In this sector more than half of the collected material is sorted and recycled separating the packaging from the rest of the recovered paper. The remaining part of the packaging is recycled together with other recovered paper, mixing them.
The dark varieties of waste paper can be used exclusively for the manufacture of packaging paper and cardboard. On the contrary, manufacturers of graphic papers (e.g. newsprint) and hygiene paper (e.g. toilet paper) require clear varieties of paper.
Traditionally, the reuse of waste paper from packaging paper and cardboard clearly occupies the first place.
However, there are also limits to the use of recovered paper. Each step of recycling involves wear, that is, an alteration of the physical characteristics due to a loss of consistency and therefore a diminished quality of the fiber material.
The fiber is shortened and can not be put together properly as required for the formation of sheets. Therefore, a part of fresh fibers is always required. In the process of recycling, fibers can be used an average of 6 times, until they have to be eliminated from the production process as a rejection along with impurities and remains of impurities.
Some technical characteristics of recycled paper are comparable to those of paper made from virgin fiber in terms of consistency, production, surface and duration, though the optical characteristics such as whiteness and purity are of a lower quality. The printing result may have limitations as to the quality.
The processing systems of waste paper have a preset station where thicker impurities are removed such as: staples, pieces of glass and wood, etc. After the waste paper material is submitted to a cleaning to prevent the finest impurities such as sand and plastic parts to enter the process. As a next step, all systems crush (dissolve) the paper used with recirculated water. Additionally, the clear varieties of waste paper, which apply to the production of graphic papers and hygiene papers, undergo a process that serves to eliminate traces of ink on paper. This mechanical chemical cleaning is carried out with chemicals like soap or caustic soda to dissolve the printing inks.
According to the above, it is therefore necessary to provide a paper made from recovered paper that has technical characteristics and a similar or superior appearance compared with the characteristics of paper made from virgin pulp fiber.